Yellow flame oil burner



Sept. 28, 1937. D. H. HILL YELLOW FLAME OIL BURNER Filed June 14, 19351227 ill Jill.-

I ven E we by merely dropping a lighted match into it, and Fig. 3 is areduced central and vertical section, 10

operating features for producing the also recited my burner, the lowerpart comprises an upright 5 tion, instead of having the oil flow andspread widened mouth portion of relatively short height 20 and also nearthe lowermost row of air-ports in ner annular flange 5 extendingradially inward 25' port wall from an air chamber surrounding thisportion 6 of the trough mouth, and desirably 30 near the lower portionof the pot wall, and also of which oil is normally supplied through anoil 35 pre-heating the air when the burner is operating pipe 8 is anannular wick W, preferably of a nonat a higher rate of oil consumption.combustible material such as woven asbestos,

(4) Proportioning the height of the said pot which desirably presentsits upper edge approxiwall to its diameter so that with air portsdismately at the same level as the top of the burner posed in horizontalrows at varying wall heights bottom 1. 4O

draft of the stack connected to the heater in of my pot type burner,which tube desirably has rises from the Wick) near the perforated riserannular flange H extending radially inward from Patented Sept. 28, 1937UNITE YELLOW FLAME OIL BURNER Dewey H. Hill, lliokomo, Ind, assignor toGlobe American Corporation, Kokomo, Ind, a corporation of lndianaApplication June 14, 1935, Serial No. 27,714

5 Claims. (Cl. 15894) My invention relates to oil burners of thesoconsuming 8 gallons in 24 hours when used in a called pot type, inwhich the flame is produced heater drum connected to a draft-producingwithin the interior of a substantially pot-shaped stack, including aportion of a heater-drum botpart of the burner. In general, the objectsof tom to which the burner is fastened, with dotted 5 my invention arethose of providing a simple, inlines indicating the axes of theinitially separate expensive and highly effigcient burner of this classflames produced when the oil supply is throttled which, when used with astack draft will proto its operative minimum. duce a clear yellow flameeven with a low rate Fig. 2 is a fragmentary plan view of the same ofoil consumption; which can instantly be lit burner.

which will avoid numerous objections heretofore with dotted linesindicating the flame produced encountered with pot type oil burners.with substantially the maximum rate of oil More particularly, myinvention aims to prosupply. vide a pot type burner having the following00- In the illustrated three-piece construction of advantageous effects:annular oil trough having concentric tubular (l) The use of a sparselyperforated pot bottom sides 9 and 2 of equal height extending upwardsand the upward feeding of the oil by a wick from for a height many timesthe width-of the annua trough surrounding the perforated bottom porlarspace between these sides, and having a upon the burner bottom to form alayer of oil in proportion to the said trough sides. This which cannotbe lighted with a mere match. widened mouth portion comprises an outeran- (2) Disposing the upper end of the wick near nular flange 3extending radially outward from air-admitting perforations in the burnerbottom, the upper end of the outer trough side '5, an inthe riser wallof the burner pot, thereby enabling from the upper end of the innertrough side 2, the combustion to be started by merely dropping and twoshort tubular portions 5 and 6 rising rea lighted match on the wick.spectively from free edges of the said two flanges.

(3) Supplying the air for the air ports in the Spanning the upper end ofthe inner tubular wall, into which chamber air is drawn upwardly;forming a part of the same sheet metal stamping thereby enabling thelowermost air ports in this with the oil trough and its Wide-mouthedupward pot wall to supply sufiicient air, when oil is fed extension, isa horizontal burner bottom l. Seatat a low rate to the wick, to maintainsmall flames ed in the annular oil trough, to the lower portion and ofuniform diameters, the combustion will Telescoped at its lower end intothe outer tube eflioient regardless of the upward and downbular portion5 of the said lower part of my Ward Shifting 0f the resulting fl in espose burner and desirably welded to this portion, is to variations in therate of oil supply and in the a perforated tube 9 which forms the riserwall 45 which the burner is used. a height approximating the radius ofits bore. (5) Providing auxiliary air ports in the burner This tube isfreely surrounded by an imperforate bottom, in addition to thosedisposed near the riser tube H] which is spaced from and mainwick, forassisting in keeping the oil vapor (which tained coaxial with the tube 9by an imperforate 50 Wall of the pot and for increasing the draft up theupper end of the riser tube It, the said flange the burner when the oilis fed at a high rate. having its inner portion welded to the upper por-Illustrative of my invention, tion of the perforated tube 9 whichconstitutes Fig. 1 is a full sized central and vertical section theriser wall of the burner pot. 1

through an oil burner of adequate capacity for The lower end of theimperforate outer tube l0 desirably has an outwardly extendinghorizontal flange l2 adapted to be welded (as at W) to a heater drumbottom [3 which has a perforation through which the said outer tube I0extends upwardly. Thus arranged, the said outer tube In together withthe top flange II respectively constitute the riser wall and the top ofan air chamber surrounding the perforated pot wall 9, within which themajor part of the air supply for the burner is warmed before passingthrough the perforations P in that pot wall into the interior of thepot.

For efficient operation, the perforations P in the pot wall 9 desirablyare distributed. uniformly circumferentially of. the said wall and alsoare distributed over a height reaching, from near the top of that wall,down to a level somewhat higher than the pot bottom I. In practice,these perforations may all be uniformlyspaced, as here shown, since theouter tubular portion 5 of the lower sheet metal part of my burner cancover an unduly low row of such perforations, thus permitting theperforated pot wall 9 to be cut from a strip of standard perforatedsheet metal. However, this strip or blank is desirably cut so that theperforations in consecutively superposed rows will be relativelystaggered, as in Fig. 1.

To co-operate with the said wall perforations and to facilitate thelighting of the burner, I provide the burner bottom I with auxiliaryperforations, the total area of which preferably is less than half ofthe total area of the perforations in the said burner wall. These bottomperforations preferably include an outer circular row of air ports prelatively close to the periphery of the bottom 1, and therefore near tothe oil vapor which is evaporated from the wick W, and additional rowsof air ports spaced farther from the wick, such as the rows of ports pand 23 When oil is first supplied to the oil trough through the oil pipe8, some of this oil is drawn up into the upper portion of the wick bycapillary action. The burner then can speedily be lit by merely droppinga lighted match on or near the exposed portion of the wick, since theneeded air will readily enter through the lower row of perforations P inthe pot wall and also through the outer row of airports p in the potbottom. The flame thenspeedily travels around the wick and the resultingwarming of the oil vapor soon causes separate small flames to be formedalong flame axis lines (such as f in Fig. 1) corresponding somewhat tothe direction of the air jets entering through the lower rows ofperforations in the pot Wall.

The heat of these flames then gradually increases the rate at which theoil is drawn up into the wick and vaporized from the upper portion ofthe wick. This heat also gradually warms the entire heater drum so as toincrease the draft in the usual stack leading from the (not illustrated)upper portion of the heater drum, so as to increase the rate of airsupply correspondingly.

Then, when the metal of the burner also becomes sufficiently hot so thatthe oil in the oil trough is considerably warmed, the burning rate aswell as the draft increase, and the petty flames (which first form asseparate petty flames) merge with one another into an annular flamewhich gradually shifts its starting point, from that shown for a'portionof this flame in Fig. 1, to the maximum-elevation shown in Fig. 3.

During this flame production, the air entering through the outer row ofair ports p in the burner bottom issues upwardly, thereby keeping therising oil vapor sufliciently near to the air-admitting perforations Pin the pot wall 9 to insure a fairly good combustion efiiciency evenwhen the flame is receiving its air supply from wall perforations belowthe mid-height of the said pot wall.

Then, when the temperature of the burner and the stack draft have bothrisen so that the flame receives most of the needed air from the higherwall perforations, this air is drawn from the upper or hottest part ofthe annular air-warming chamber between the tubular walls 9 and I0, sothatits temperature increases the efficiency of the combustion.Consequently, I have found my here illustrated burner to show acombustion efficiency of from 90 to 94 percent with fairly cheap gradesof oil, when the burner is operated at approximately its maximumcapacity. Since the draft is most intense along the flow lines of theflame-precipitating air jets, the amount of air then drawn through thelower wall perforations and through the air ports in the burner bottomis relatively small, so that the loss of heat up the stack is small.

Moreover, when the rate of oil supply is reduced, so that the burnertemperature is lowered and the stack draft is decreased, the startingpoints of the flame gradually shift downward, and the reduction of thetemperature of the oil trough causes the rate of oil vaporization todiminish also. With the here disclosed burner construction, thisthrottling of the oil supply can be continued until the flames areconfined to petty ones for which air is supplied only by lowermost rowsof perforations in the pot wall 9; and even with the reduced draft theflow of air through the outer row of air ports 12 in the burner bottomwill then keep the oil vapor sufficiently close to the said pot wall tomaintain the flame. Consequently, I have found that the oil consumptioncan be cut down to approximately one-sixteenth of the maximum for whichmy burner is constructed, without having the flame become smoky orextinguish.

I have also found that with suitably proportioned sizes of theair-admitting ports, my burner will give a clear yellow flame at allrates of oil consumption. If the oil should be supplied at an excessiverate when the burner is first lighted, the widened mouth extension ofthe oil trough will afford a chamber for storing a reasonable excess ofthis oil until it is vaporized.

In practice, my burner will show most of its advantages even if theburner bottom has only the radially outer row of air ports 19 Indeed,many of its advantages would still be obtained if this burner bottom isimperforate, but the flame would not be as clear, and an overflowing ofoil upon this burner bottom would then cause the objectionableinadequate combustion of this oil and the still more objectionablesmouldering and depositing of carbon which I avoid by the perforationsin my burner bottom.

Other changes might also be made while still permitting my burner topresent some of its important advantages, as for example in theproportioning of some of its parts, provided that my burner is used witha stack draft. However, I

preferably make my perforated pot wall only about half as high as itsdiameter. With such a wall, the high temperature of the flame, when theburner is operating at or near its maximum capacity (as indicated inFig. 3) causes the air to be drawn mainly through the upper rows ofperforations in the pot wall, and the warming of this air while movingupward within the shield tube ii probably contributes materially to thetemperature of the flame so as to account (at least in part) for thehigh combustion efiiciency.

Moreover, While my burner is allied in some respects to pot type burnerswith imperforate bottoms, and in other respects to blue flame burners inwhich the oil vapor rises between two perforated tubes, I have found myburner to have approximately four times the oil-consuming capacity (inproportion to its diameter) of either of the just mentioned older types,and have found this to be true even in comparison with a pot type burnerconstructed with greatly enlarged air ports in the upper portion of itspot wall.

Incidentally, it will be noted that my entire burner is exceedinglysimple and inexpensive in construction, that is can easily be fastenedto and supported by a heater drum bottom; that it affords ready accessto the wick in case this needs to be replaced; and that all of theair-adrnitting ports can easily be cleaned, either by brushing theinterior of the pot or by merely blowing air into it.

While I have shown the body of my burner as of a three-piece sheet metalconstruction, the three parts are fastened to and substantially sealedto one another. Consequently, I have a substantially unitary bodycomprising these parts: an outer annular portion of an inverted channelsection in which the inner wall 9 has air ports P distributed over itsgreater portion; an annular oil trough opening into the bore of the saidinner wall 9 and preferably having a widened upper portion of relativelysmall height in proportion to the part of the trough below this widenedmouth portion; and a substantially horizontal (or at least not upwardlyconcaved) disklike bottom part i spanning the inner edge of the mouth ofthe trough and provided, at least adjacent to its periphery, with airports p In practice, I preferably make the spacing between the twoconcentric cylindrical-tubular walls 9 and Hi of the outer (invertedchannel part) less than half of the height of these walls, so as toreduce the volume of air between these walls, thereby insuring anadequate heating of this air for producing a highly efficient flame whenthe burner is in operation.

Moreover, the character of the flame remains the same at all burningrates; and the desirably provided widening of the trough mouth allowsthe circular bottom portion of the burner to be at a level near that ofthe lowermost perforations in the pot wall and accommodates an overflowof oil without having the oil spread on the said bottom portion.

I claim as my invention:

1. An oil burner for use with a stack draft, comprising a circular andsubstantially horizontal bottom portion; an annular oil trough havingthe upper end of its inner wall sealed to and depending from theperiphery of the said bottom portion, the said trough having a widenedupper portion; a non-combustible annular wick disposed within the troughand extending substantially the entire length of the trough, the wickhaving its upper edge approximately at the level of the said bottomportion; an upright cylindrical-tubular pot Wall sealed at its lower endto the upper end of the outer wall of said trough, the said pot wallbeing provided with perforations distributed both circumferentially andvertically from a level somewhat higher than the said bottom plate to alevel near the upper edge of the said pot wall; an imperforate annularflange sealed at its inner edge to the upper end of the said pot wall,and an outer imperforate tubular wall member depending from the outeredge of the said flange, the outer wall member extending downwardlybeyond the level of the lowermost perforations in the said uprightperforated pot wall; and means for feeding oil into the lower portion ofthe said trough.

2. A yellow flame oil burner comprising an inverted annulartrough-shaped member of considerably greater height than the radialspacing of the two riser walls of the trough formation, the inner wallof which is provided with perforations distributed throughout the lengthof that wall and over the major portion of the height of that wall; anannular oil trough of considerably greater depth than width having awidened mouth portion, and having the upper end of its outer wall sealedto the lower end of the inner wall of the aforesaid member; a disk-likehorizontal burner bottom spanning and sealed to the upper end of theinner wall of the said trough; means for feeding oil into the oiltrough; and a noncombustible wick disposed in the said trough andextending substantially the entire length of the trough, the said wickreaching from approximately the bottom of the trough to approximatelythe level of the said burner bottom; the burner bottom being providedwith air-admitting perforations, the total area of which is less thanhalf the total area of the perforations in the inner wall of the firstnamed member, the perforations in the said member and in the burnerbottom comprising the sole means for admitting air to the burner.

3. An oil burner as per claim 1, including an annular and generallyhorizontal supporting flange sealed to and extending radially outwardfrom the lower end of the said annular pot wall member.

4. An oil burner as per claim 1, in which the said bottom portion isprovided near its outer edge with a circular row of perforationscooperating with the lowermost of the perforations in the said pot wallfor supplying all the air for combustion of the oil when the oil is fedat a low rate to the said trough.

5. A yellow flame oil burner as per claim 3, in which the depth of thewidened mouth portion of the trough is less than half the total depth ofthe trough, and in which the said widening is at both sides of the upperportion of the wick, whereby the spacing of the walls of the said mouthportion of the trough from the upper part of the wick permits oil vaporto evaporate freely from both sides of the said upper part of the wick.

DEWEY H. HILL.

